Multiplying Complex Numbers: (-11 - 7i)(2 + 6i)
This article will guide you through the process of multiplying two complex numbers: (-11 - 7i) and (2 + 6i).
Understanding Complex Numbers
Complex numbers are numbers that can be expressed in the form a + bi, where:
- a and b are real numbers
- i is the imaginary unit, defined as the square root of -1 (i.e., i² = -1)
Multiplication Process
To multiply complex numbers, we use the distributive property, similar to multiplying binomials.
-
Expand the product: (-11 - 7i)(2 + 6i) = (-11 * 2) + (-11 * 6i) + (-7i * 2) + (-7i * 6i)
-
Simplify each term: = -22 - 66i - 14i - 42i²
-
Substitute i² with -1: = -22 - 66i - 14i - 42(-1)
-
Combine real and imaginary terms: = (-22 + 42) + (-66 - 14)i
-
Final result: = 20 - 80i
Therefore, the product of (-11 - 7i) and (2 + 6i) is 20 - 80i.
Key Points
- Remember to distribute each term of the first complex number to both terms of the second complex number.
- Replace i² with -1 whenever it appears in the multiplication.
- Combine real and imaginary terms separately to express the final answer in the standard form a + bi.